Medical lasers have been used in various practice areas, such as, for example, urology, neurology, otorhinolaryngology, general anesthetic ophthalmology, dentistry, gastroenterology, cardiology, gynecology, and thoracic and orthopedic procedures. Generally, these procedures require precisely controlled delivery of energy as part of the treatment protocol.
Many tissue-ablative laser systems, such as the American Medical Systems GREENLIGHT® Laser System, utilize a frequency-doubled Nd:YAG laser operating at 532 nm. This wavelength, provided in a quasi-continuous mode, is used at high power levels for efficient tissue ablation. The frequency doubled Nd:YAG laser can be pumped by CW krypton arc lamps and can produce a constant train of laser light pulses. When ablative power densities are used, a superficial layer of denatured tissue is left behind. At high powers, 532 nm lasers induce a superficial char layer that strongly absorbs the laser light and improves ablation efficiency.
Many surgical laser procedures utilize a surgical probe, which generally comprises an optical fiber and a fiber cap over a distal end of the optical fiber to form a probe tip. A laser source delivers laser energy through the optical fiber to the probe tip where the energy is discharged through the fiber cap and onto desired portions of the targeted tissue.
The laser energy may be directed laterally from the probe tip by reflecting the laser energy off a polished beveled surface at the distal end of the optical fiber. The fiber cap seals a cavity containing a gas (or vacuum) that maintains the necessary refractive index difference for total internal reflection at the beveled surface.
The fiber cap may be protected from tissue adhesion and other causes of fiber cap degradation by surrounding the fiber cap with a second cap, as described in U.S. Pat. No. 7,909,817, which is incorporated by reference herein in its entirety.
There is a continuous need for improvements in laser fiber probe tips, such as improvements that reduce manufacturing costs and increase reliability. Embodiments described herein provide solutions to these and other problems, and offer other advantages over the prior art.